Joint for demountable steel structures



Aug."17, 1943. J. HEITNER 2,326,941

JOINTS FOR DEMOUNTABLE STEEL STRUCTURES Filed Jan. 30, 1941 N L 15 18 A 1a r /J t QLN @ wwwgg The hvehti je ate to jo nt i01 demount able steel struetu resf-m'ade of tubes;

' structions' in which the jointing" elements con:

I sist of sleeves madejin two ha1ves,rwhich;seoure I the connection of "the elements by means' 0 f vi screw-bolts. "In these joints [the axial stresses are; I taken up} through the friction effected by Y the pressure of the; sleeves. V'Ihusthe'transmit- I 7 table stresses are by. the I frictionat the .s There arev also known such.demountableoonstructions in which. the ends; of theitube'sito vbe 1 connected are coni'cally enlarged and fit intQ the,

{accordingly ;shapedgroove of theg sle'eve. ,In

I wanceofithfecone against bending. 1

In order tdprevent this bendingofthe oone I I it'is usualrto' insert Vi-shaped supports'in the "of the conelaysjperfectly on the corresponding .i part of the inner support Should anoverload'f.

or a sudden impact ocour, I the tubesl to ,be' 'i con v nected start to 'move in lthe direction of the axial stress; Qn ac counti of" the-innersupport not niovin'g' 'withYth e tubes, the cone wilLb e -leftunfsupporte'd. and he cone'wi 1l bebentbaok leaving v the tubes slip ut/hem the sleeve.

I 'I' he' invention bonsists. "in. 'demountable joints f I.

I for demountable and reere'ctablfestruoturaleon I J stru'ctions, which jointsl being 'madef of two tubes having coincidal axes whereby, the two i tube-ends to be connected arehe d together by I means of a grooved sle'ev'efmade "of twojshells united byscrew bolts.

.. nected stiffening disks are inse'rted and f a'stened' I to the respective tube end in such-.manner that at the end 'of each. tube aflange is iormedjthe resistance of which against shearing stress is greater than the resistance ofsuch joints having n I110, disks inserted. '5 1 In one arrangement according totheinven leader a sudden impact.

1 arrangement in which the ends of thej tubes are I I "I'herea're 1 known a number'of such demountable steel=con The essential feature of the invention consists 4 in that into each of the twoitube endsto be conconically enlarged and a conical disk ijsins'erte'd i ,1

disk willmove with thetube in cas e oi' an over "1 a y The same resultis obtained with the second .fof carrying out the invention. i I

Figgljis a; longitudin conedftube ends. J

en'dsef v inner 'groo'vesllitjand l6 ln ,-which,the oones' sit.

29*Th'e fastening of :theshell is f the ,Iscre'w-bdlts IIaand lita .thes'hellsliand l'5". vIn casethetubes H by acting forcesfhigherthan statistically figured 1 thtubes would-"begintofslip, the disos .13 and .13

comes against-bending forces.

- preferable 2 td f form the; fl nges; I2]? and ll 'by a resulting irointhe tension force P.

The drawing shows the stiffening elements 13 1 and l9 fastenedto I-thetube ends'by'electric weld- I ing; Said elements maybe conne'cted also with" sgrewing or some 'othernieans;

J What I claimjis: 1

' The aecornpanyi n g dravv'ing shows exam p les a1 sectilon of'ajoint'with I V sectional view io the z: 2"jer r e 1e g1tiidi a1 se t'ion 'o ffe. joint 7th flanged plugs-I insertedf in, the t b j OnjFigures g1 d 2 the ends oi the tubes? I I a and H1? are conically enlarged'atn and VI2,'. ;In". I I the inner. part Iof the' conesthe stiifening disks 1'3 and l3 arei in'ser;ted'andl'fastened"bymea'n of electric 'Weld-ixig'j; M G:- The-tube braces; are, I v connectedbymeansfoi shellsjwand-J5 having Pr vided thrw h' a 'In. the second method shown'o n'fFig. 3 the ends? hollowpart er the tube end; This arrangement II I 8 and l8'- o f the tubes to be connected'arestifi-j I V g works sufiiciently; only as long-asfthe inner part vened by plugs l 9 and-l9 fastened through eleof trio welding at Mend-29 JI'he'fianges U and 22!: Of the plugssit' in thef groove r d lli'fof I lild ll"; Largundejfi a tension force P; this forc tends topullthem r I eaparta'nd to bend'thecones back j 'I'hediscsjii and' l 3' set in thetubes s'tifienthe conesa'gainst I bending; 'If in caseof notexactvworkmanshipor,

J' move with them .ensuringasteady support of the y In the' second method shown .i'n Fig; Sfthe flanges 52L and 1|? are cylindrical-and fit'into,

. the-grooves andVI G', thus transmittingthe ten- 7 fsionfstre'ss t'o thefconnectingsleeve, Itwo ul dbe meansof bending out the walls oi; the tubesbut I I in; this case the shearing force allowable: would be llmit'ed to the. thiokness ofthejwallx In form- 1'.'The combination'ofa'pair of tub es ih n t end relation; each having an outflare'd end por I tionforming an annular-flangeand anend insert s r shells tosjetherja'ribfiilldfsaidtubeiendslf Y 2. The combinationrot a pair of tubes movement'with respect'thereto, the insertsupporting the outflared end portion'ot the tube V against collapse, a pair of shells engaging around r the tubes andtogether defining .a generally. an-

'nular inner groove for rfeceivi ng bothsaidflanges,

and means for r'eleasably clamping said; paii of to end relation, eachihaving'a eonioally-enlarged endportlon forming an annular'fiangeianjd'a gen j erally disc shaped fixed insert positioned tosup-g 7 port the conicallyenlarged endiportion'against. collapse, and apair of shells-engagingaround the tube ends and togetherdefl 'ning a generallyjan' f" nular inner groove forreoeiving bothisaid flangesand means for releasably clamping said pair of shells together aroundthe tubeends. l l x 3. The combinationgwitha. pair'of tubes in a to end relation, each tube end having a relatively flxed lend insert and'an annular endflange, of a ;pair' of shellsengagingaround the tube ends and se'curedito the tube as to have no relative together defining a generally I annular inner groove for receivingv both said flanges and means v forreleasably clamping said pair-of she'llstogether around the tube ends. a

4. The combination of apair of tubes in end Q to end relation, each having a, conically enlarged I end portionforming an external flange and a a jjjfla'redg; I v

largedi'end portion 'withxit's peripheral edge supc'surface; 5.1,fdisk inserted in the enportably engaging the flared inner Surface means fixingtheldiskf in place to positively prevent axial movementpt the disk' relative tothe enlarged end portion; a 'paif'of shells enclosing the tube ends -j and together defining an annular groove receiving theflangejs on the tube ends,'and means for releasably elampi ngz the shells togetherj around he been -f 5, The combination recited in claini- 4 wherein said peripheral edge is bevelledjto substantiallyv 7 "conform to the flared inner surface.

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